A permanent magnet motor in an electric motor system can be damaged when the temperature of stator windings of the permanent magnet motor become overheated. Typically, the temperature of the stator windings is measured by a temperature measurement sensor, such as a thermistor, installed on one of the phases of the electric motor stator winding. Assuming balanced three phase currents are flowing in the stator windings, the single temperature measurement sensor may adequately estimate the temperature of all three phases. At or near zero speed, however, no current may be flowing in the phase of the electric motor stator winding where the sensor is installed or, at certain speeds, unbalanced currents may be flowing in the three phases of the stator windings. Under these conditions, the single temperature measurement sensor will not correctly report the actual temperature of the electric motor and, consequently, the electric motor can be damaged by overheating.
Accordingly, it is desirable to provide a method and apparatus for preventing overheating damage to stator windings of the electric motor. In addition, it is desirable to provide temperature sensing for the electric motor at all speeds including at or near zero speed. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.